A nonlinear analysis is developed for eddy-current couplings in feedback control systems. The analysis makes use of the describing function method to predict transient response.

Effects of the nonlinearity are discussed and backed with an analog computer study. Conclusions arrived at show the absquare nonlinearity to be advantageous under conditions of zero steady state loading or offset.

Under conditions of steady state loading, shifting of the load operating point causes a wide variation in response. This situation is remedied with nonlinear compensation.